A hanger hinge is used to suspend a hinged panel, or a pair of hinged panels, from an overhead horizontal track while permitting the panels to pivot about a vertical hinge axis. Typically, the panels are panels of a folding door, window or similar closure. If the hanger hinge is used to suspend the end panel of a series of panels, it normally has one hinge leaf fixed to that panel. If the hanger hinge is an intermediate hanger used to suspend a pair of adjacent panels, it has a pair of hinge leaves, each fixed to a respective one of the pair of adjacent panels.
Throughout this specification, where the context permits, the term “panel” is intended to refer to a generally planar closure component of a folding door, window, shutter, screen or like closure. The invention will be described with particular reference to its application to panels of a folding door, but the scope of the invention is not limited thereto.
Typically, each hanger hinge (except the hanger hinge nearest the jamb) depends from a respective wheeled carriage which rides along the track. The combination of each hanger hinge and its carriage forms a carrier hinge assembly. An example of a known carrier hinge assembly is illustrated in our Australian Patent No. 726943.
A hanger hinge typically comprises an upright hanger bolt which serves as a hinge pin for the hinge leaf or leaves pivotally mounted thereon. The bottom end of the bolt is threaded to receive a nut thereon. The hinge leaves, which are axially slideable along the hanger bolt, rest upon the nut and are supported thereon. The position of the nut on the hanger bolt therefore determines the position of the hinge leaves relative to both the hanger bolt and the track from which the hanger bolt is suspended. Since the hinge leaves are fixed to the panels in use, the height of the panels can be adjusted by rotating the nut to vary its position along the threaded end of the hanger bolt.
Height adjustment of the panels is usually required from time to time to correct out-of-square movements of the panels and to prevent the door panels from sticking, or otherwise to facilitate smooth movement of the door panels. It is important to ensure that once the hanger hinge has been properly adjusted, it does not lose its adjustment, i.e. that there is no undue rotation of the height-adjusting nut.
It has been found that with conventional hanger hinges, repeated opening and closing of the panels can result in rotation of the nut, and hence loss of adjustment.
Hitherto, a second (locking) nut has been used on the hanger bolt to lock the height-adjusting nut in position. However, such locking nut arrangements are not always effective. Two spanners are usually required to adjust the height of the panels, and due to the positioning of the nuts in close proximity to the panels, damage may be caused to the panels through spanner slippage. Moreover, the nuts are not aesthetically pleasing.
Our U.S. Pat. No. 6,618,900 discloses a lockable carrier hinge assembly in which height adjustment is achieved by threading the hanger bolt into the carriage. The hanger bolt has a fixed nut or head at its bottom end. Once adjusted, the hanger bolt is locked to a hinge leaf, to prevent relative rotation therebetween.
Although the lockable carrier hinge assembly of U.S. Pat. No. 6,618,900 has been found to be satisfactory for most commercial and residential applications, it may not be the optimum design for suspending large and heavy door panels.
It is an aim of this invention to provide an adjustable hanger hinge which overcomes or ameliorates one or more disadvantages of the prior art, or which at least provides the consumer with a useful choice.